Incoming Mail Server: pop.mail.yahoo.com – Use Port 465 and SSL
Outgoing Mail Server: smtp.mail.yahoo.com – Use Port 995, SSL and authenticate with the outgoing server
AT&T changed their mail server names to
Incoming server: inbound.att.net – Use Port 995, SSL enabled.
Outgoing server: outbound.att.net – Use Port 465, SSL enabled. On the Outgoing Server tab, enable authentication.
We've had a lot of complaints about the Enter Network Password dialog box constantly popping up. It's sometimes accompanied by a send/receive error:
'Your e-mail server rejected your login. Verify your user name and password in your account properties. Under Tools, click E-mail accounts. The server responded: -ERR [AUTH] invalid user/password'
The usual response is to see KB 290684 for steps to fix the corrupt password cache, this may not be the problem if you use a smartphone.
After trying "everything", one observant user realized the dialog stopped coming up when his iPhone was turned off.
While it may be something with the network (as some AT&T users believe), Outlook has always been sensitive to mailbox locks, more so than other email clients.
Since not reading your mail on a smartphone is not a viable option for most users, you can reduce the frequency of the dialog by decreasing how often Outlook and the devices check for new messages. The setting should always be at least 8 – 10 minutes (be kind to the mail server!) Increase the minutes between checks on the devices you use less often. Switching to IMAP (if available) will also eliminate the problem.
For complete coverage, see The Never-Ending Network Password Dialog
Published October 4, 2011. Last updated on May 8, 2014.